Display screens are the primary visual display interface to a computer. One problem with these visual display screens is that they are limited in size, thus presenting a challenge to user interface design, particularly when larger amounts of information is to be displayed. This problem is normally referred to as the “screen real estate problem”.
Well known solutions to this problem include panning, zooming, scrolling or combinations thereof. While these solutions are suitable for a large number of visual display applications, these solutions become less effective where the visual information is spatially related, such as maps, newspapers and such like. In this type of information display, panning, zooming and/or scrolling is not as effective as much of the context of the panned, zoomed or scrolled display is hidden.
A recent solution to this problem is the application of “detail-in-context” presentation techniques to the display of large surface area media, such as maps. Detail-in-context presentation techniques take on many forms and are useful for displaying large amounts of information on limited size computer screens, and are becoming more important with the increased use of hand held computing devices such as personal digital assistance (PDA's) and cell phones.
Now, in the detail-in-context discourse, differentiation is often made between the terms “representation” and “presentation”. A representation is a formal system, or mapping, for specifying raw information or data that is stored in a computer or data processing system. For example, a digital map of a city is a representation of raw data including street names and the relative geographic location of streets and utilities. Such a representation may be displayed visually on computer screen or printed on paper. On the other hand, a presentation is a spatial organization of a given representation that is appropriate for the task at hand. Thus, a presentation of a representation organizes such things as the point of view and the relative emphasis of different parts or regions of the representation. For example, a digital map of a city may be presented with a region magnified to reveal street names.
Detail-in-context presentations allow for magnification of a particular region of interest (the “focal region”) in a representation while preserving visibility of the surrounding representation. In other words, in detail-in-context presentations focal regions are presented with an increased level of detail without the removal of contextual information from the original representation. In general, a detail-in-context presentation may be considered as a distorted view (or distortion) of a portion of the original representation where the distortion is the result of the application of a “lens” like distortion function to the original representation. A detailed review of various detail-in-context presentation techniques may be found in a publication by Carpendale, Marianne S. T., titled “A Framework for Elastic Presentation Space” (Burnaby, British Columbia: Simon Fraser University, 1999)) and incorporated herein by reference.
One shortcoming of current Electronic Presentation Space (EPS) graphics technology and detail-in-context presentation methods is that they are computationally inefficient. Considerable computer processing is required to distort a given presentation so as to produce a detail-in-context “lens”, and to move the lens through the data with adequate performance to provide an acceptable level of interactivity to the user.
Another shortcoming lies in the level of accuracy of magnification that these methods provide, since detail-in-context methods such as those described in Keahey's NonLinear Magnification (Keahey, T. Alan, Nonlinear Magnification (Indiana University Computer Science, 1997)) require an interative approach to transform a data representation into a detail-in-context presentation at a given desired magnification.
A need therefore exists for a method and system that will allow for the effective implementation of EPS graphics technology for the online and electronic presentation of printed media. Consequently, it is an object of the present invention to obviate or mitigate at least some of the above-mentioned disadvantages.